1. Field of the Invention
The present invention generally relates to heat exchanger construction and assembly methods. More particularly, this invention relates to a baffle and method for creating at least two isolated fluid circuits within a heat exchanger.
2. Description of the Prior Art
Baffles are used in a variety of applications to block and direct the flow of fluids and gases through tubular members, such as a manifold of a heat exchanger. Heat exchangers typically include tubes interconnected between a pair of manifolds. To optimize heat transfer efficiency, the flow of a heat transfer fluid (gas or liquid) through the tubes is often controlled by placing baffles at certain points within the manifolds, such that separate and parallel flow regions can be established within the heat exchanger by appropriately routing the fluid through its tubes.
The prior art has suggested various baffle designs and methods for installing baffles within heat exchanger manifolds. One example is to use cup-shaped baffles that are installed within the internal passage of a manifold and then brazed in place. Brazing is desirable for forming a high-strength, fluid-tight seal with a baffle, particularly if the heat exchanger has a brazed construction. However, a difficulty with cup-shaped baffles is that braze flux may remain trapped within the manifold, which can corrode the interior of the heat exchanger. Another approach is the use of partitioning plates inserted through circumferential slots formed in the wall of a heat exchanger manifold. Examples of partitioning plates known in the art are disclosed in U.S. Pat. Nos. 4,825,941, 5,125,454, 5,348,083, 5,743,329 and U.S. Pat. No. Re. 35,742. Though the slots can facilitate removal of residual braze flux from the manifold, they can substantially weaken the manifold wall, reducing its capacity to withstand numerous temperature and pressure cycles. In addition, partition plates of the prior art are prone to being dislodged prior to being brazed to the manifold, such that leaks between flow regions can occur through a gap between the plate and manifold wall.
In view of the above, it would be desirable if an improved baffle design were available that avoided or minimized the shortcomings of the prior art, including the concerns for flux contamination, reduced wall strength and the likelihood of leaks.